Fine particles from aircraft exhaust become more harmful over time, lab tests suggest

Fine particulate matter consists of tiny particles with diameters in the nanometer range. They are produced, for example, by fuel combustion, remain suspended in the air and can penetrate deep into the respiratory tract. There, they can trigger oxidative stress, a process that promotes inflammation and, over the long term, can lead to serious health problems such as respiratory or cardiovascular diseases. Scientists call this harmful property the particles' oxidative potential.